Most of the water reaching the leaves:
1. is used in photosynthesis.
2. is used up in plant growth.
3. is lost by transpiration.
4. is stored in the petiole.

In a guard cell:
I. The outer walls are thick and elastic
II. Cellulose microfibrils are oriented longitudinally
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect

You are asked to measure transpiration rates on both the surfaces of Sunflower leaf. The transpiration rate is expected to be:
1. Lesser on upper surface and more on lower surface
2. Lesser on lower surface and more on upper surface
3. Equal on both the surfaces
4. Zero on upper surface

Cohesion, adhesion and surface tension provide water with a high tensile strength that means that it:
1. is capable of rising in a thin tube
2. has a low specific heat
3. resists a pulling force
4. is a universal polar solvent

Consider the following:
I. Creation of pull for absorption and transport in plants
II. Supply of water for photosynthesis
III. Transport of minerals from leaves to all parts of a plant
IV. Cooling of leaf surface
V. Maintenance of shape and structure of plants by keeping the cells turgid
Functions of transpiration include:
1. All
2. All but III
3. All but V
4. All but III and IV

The evolution of C4 photosynthetic system is probably one of the strategies for:

The control points where a plant adjusts the quality and types of solutes that reach the xylem are:

Unloading of mineral ions occurs at the fine vein endings through:
1. diffusion and, are passively taken up by the sink cells
2. active transport and, are passively taken up by the sink cells
3. diffusion and, are actively taken up by the sink cells
4. active transport and, are actively taken up by the sink cells

An analysis of xylem exudates will show that most of the nitrogen is carried as:
1. Inorganic ions
2. Ammonia dissolved in water
3. Dinitrogen
4. Organic compounds such as amino acids

Unlike xylem, the movement of sap in phloem is:
1. essentially unidirectional
2. from a sink to a source
3. independent of movement of water
4. in any direction from source to a sink